The major aim of this grant is to assess the effects of dietary alterations on changes in the metabolism and turnover of elastin. Most recently some evidence has been provided that proforms of the known soluble precursor of fibrous elastin exist. Soluble elastin or tropoelastin appears to be synthesized in vitro. This effect does not appear to be related to changes in the rates of degradation of tropoelastin, which is not altered by dietary cholesterol. Evidence has also been obtained that tropoelastin is the most immediate precursor to fibrous elastin. These relationships and characterization of the proteins involved are currently being investigated. Further work will also involve studies on the calcification of arterial tissue. BIBLIOGRAPHIC REFERENCES: Rucker, R.B. and Tinker, D. (1977) Arterial elastin structure and metabolism. In: International Reviews of Experimental Pathology, Academic Press (in press). Rucker, R.B. and Murray, J. (1977) Nutritional copper deficiency and penacillamine administration: Some effects on bone collagen and arterial elastin crosslinking. In: Crosslinking in Proteins, Plenum Press (in press).